Electric connectors

ABSTRACT

An electric connector for use with flat multiple-conductor cables has two body members, one of which is attached to the cable. The other body member may be secured to the first so as to sandwich part of the cable between them. One body member carries a plurality of conductive connection members, and the other body member carries conductive contact members. The contact members are arranged so that one end engages with a connection member and an intermediate part is forced into contact with a cable conductor as the connector is assembled on the cable.

United States Paten 91 Halley et a1.

[451 Nov. 19, 1974 1 ELECTRIC CONNECTORS [75] Inventors: David Walker Halley, Dundee;

Russell Allan Leather, Perth, both of Scotland [73] Assignee: Ferranti Limited, Hollinwood,

Lancashire, England [22] Filed: May 19, 1971 [21] Appl. No.: 144,871

[30] Foreign Application Priority Data May 30, 1970 Great Britain 26197/70 [52] U.S. Cl 339/17 F, 339/91 R, 339/99 R, 339/210 M [51] Int. Cl. H011 13/54, HOSk 1/12 [58] Field of Search 339/17 F, 17 L, 17 LM,

339/17 M, 176 M, 176 MP, 176 MP, 91 R, 75 MP, 75 M, 75 R, 125 R, 126, 156, 59 R, 59 M, 217 R, 217 S, 18 R, 18 P, 95-99, 210, 211, 242, 244, 249, 196, 195, 206, 207, 208,

[56] References Cited UNlTED STATES PATENTS Robbins 339/198 S 3,149,896 9/1964 Hall 339/17 F X 3,150,909 9/1964 Deverell 339/97 P 3,235,833 2/1966 Elm 339/97 P 3,245,024 4/1966 Evans 339/103 M X 3,436,715 4/1969 Matthews 339/17 F 3,590,330 6/1973 Teagno et a1. 339/17 M X 3,706,954 12/1972 Krafthefer 339/17 L Primary ExaminerFrancis K. Zugel Assistant Examiner-Terrell P. Lewis Attorney, Agent, or Firm-Cameron, Kerkam & Sutton [5 7 ABSTRACT An electric connector for use with flat multipleconductor cables has two body members, one of which is attached to the cable. The other body member may be secured to the first so as to sandwich part of the cable between them. One body member carries a plurality of conductive connection members, and the other body member carries conductive contact members. The contact members are arranged so that one end engages with a connection member and an intermediate part is forced into contact with a cable conductor as the connector is assembled on the cable.

6 Claims, 9 Drawing Figures PATENTE RSV I 91974 SHEET 10F 2 ELECTRIC CONNECTORS This invention relates to electric connectors, and in FIG. 5 is a sectioned side view of the member of FIG. 4 carrying a contact member;

FIG. 6 is a plan view of a multiple-conductor cable prepared for attachment to the connector;'and

ventional construction. The elongated plastic body of r the cable acts both as insulation and spacing between the conductors, and cables of this type may be produced with consistent electrical characteristics. Usually the conductors themselves are flat.

The main problem with flat cables of this type has been the difficulty in making a reliable termination or connection to the cable without a complex and costly connector. Some types of connector have required soldering, welding or wrapping operations to connect the individual conductors to the contacts of the connector. These are time consuming to form, and are not easily disconnected unless they form part of a plug-andsocket connector. Other types of connector employ members which cut into or pierce the conductors. These connectors tend to weaken or damage both the conductors and the insulation. Where the contacting surfaces are bare metal, high pressures are required to ensure metallic contact and it has been found difficult to maintain these pressures under all conditions.

Certain connectors require precious metal plating on the terminations to ensure good contact. Much lower pressures are required to ensure metallic contact with precious metal surfaces, but the plating process is costly.

It is an object of the invention to provide a simple and inexpensive connector which effects satisfactory connection to a flat multiple-conductor cable without the above-mentioned disadvantages.

According to the present invention there is provided an electric connector for effecting connection with the conductors of a flat multiple-conductor cable which includes a first body member of electrically insulating material arranged for attachment to the cable; a second body member of electrically insulating material capa' ble of being secured to the first body member so as to sandwich part of the cable between the two body members; at least one conductive connection member carried by one of said body members; and at least one conductive contact member having a resilient elongated portion and attached at one end to the other body member and arranged for engagement by the other end with a connection member, the contact member being shaped such that the action of securing the two body members to one another and to the cable causes an intermediate part of the contact member to bear upon a conductor of the cable from which the insulation has been removed, thereby connecting said conductor to said connection member.

An embodiment of the invention will now be described with reference to the accompanying drawings, in which:

FIG. 1 is a sectioned perspective view of one body member;

FIG. 2 is a sectioned side view of the member of FIG. 1 carrying a connection member;

FIG. 3 is an end view of the connection member of FIG. 2;

FIG. 4 is a sectioned perspective view of the other body member;

FIGS. 7, and 9 illustrate the method of attaching the connector to' the cable.

Referring now to FIGS. 1 and 2, one body member forms the base of the connector, and is moulded from an electrically-insulating material such as a thermoplastic material. Basically the base 10 consists of a rectangular block of material having formed in one surface a number of elongated recesses 11 arranged to receive the connection members of the connector. One end of each recess 11 passes through the moulding and extends to one edge as indicated at 12. The other end of each recess has a small lip 13 formed level with the surface of the moulding. In line with each recess, and adjacent to the lips 13, are a plurality of projecting spigots 14, each having a notch 15 formed in one edge. A groove 16 is formed across the base moulding 10, intersecting each recess 11.

Each connection member is formed of electricallyconducting material and has the form shown in FIGS. 2 and 3. Shown generally at 17, each member may be regarded as comprising three parts. The main body of the connection member is of a form which may be accommodated within a recess 11. A terminal post 18 is provided for connection to an external conductor or wire, whilst the other end of the connection member is slightly bevelled, as shown at 19. The connection member also carries a projecting post 20, the top of which is extended sideways as shown at 21 in FIG. 3.

The connection member 17 is inserted into the base moulding l0 simply by passing the terminal post 18 of the member through the recess in the moulding and snapping the bevelled end 19 under the lip 13 on the moulding. After all the connection members have been inserted into the moulding, a strip 22 of a hard insulating material, such as a thermosetting plastic, is placed in the groove 16, resting on each connection member as shown in FIG. 2.

The second body member 30, shown in FIGS. 4 and 5, forms the cover of the connector, and is also formed from an electrically-insulating material such as a thermoplastic material. The moulding has a number of recesses 31 formed in it, each of which contains a projecting tongue 32. A web 33 is formed across one end of the recess, and the moulding also carries a number of hooks 34 for engaging the base member of the connector. These hooks project into apertures 39.

Each recess 31 in the cover 30 contains a contact member 35 made of electrically-conductive material. Each contact member is in the form of a lever, having the elongated end retained between the web 33 and the moulding by a pair of projections 36. The contact member has a portion 37 which maybe referred to as the toe of the contact, and a portion 38 which may be referred to as the heel. The elongated portion of the contact member is resilient and forms the longer arm of the lever.

The cable with which the connector is to be used takes the form of a strip of insulating material in which are embedded a number of conductors. FIG. 6 shows a plan view of a length of cable, showing the conductors 40 embedded in the flexible insulating material 41. Inorder to prepare the cable for use with the connector it is necessary to removea strip of insulation 42 from one side of the cable so as to expose the conductors 40. In addition, two rows of apertures have to be formed through the insulating material 41 alongside the conductors. One row of apertures 43 is formed within the region 42 from which the insulation has been removed, whilst the other row of apertures 44 is formed through the full thickness of the insulation. The longitudinal spacing between the apertures is determined by the distance between the spigots 14 on the base moulding and the projecting post 20 on the positioned connection member.

FIGS. 7, 8 and 9 illustrate the use of the connector described above. FIG. 7 shows the prepared cable and the base 10 of the connector, with the spigots l4 and posts on the connector projecting through the two rows of apertures through the cable. It will be seen that;

the exposed portion of each conductor 40 is located over the strip 22 of material carried in the groove 16 in the base of the connector. Although the post 20 on each connection member passes through the insulation of the cable, the top 21 of the post 20 is displaced sideways so that it is located directly above a conductor 40.

The form of the post 20 of the connection member 17 may be varied so long as the top part 21 overhangs the conductor 40 of the cable. Connection memebers may be made by pressing or machining. The contact members 35 may be secured to the cover by means other than the projections 36 shown and described.

It is possible to use the connector described above to interconnect two cables whilst at the same time providing for external connections. in such a case, one of the cables is prepared and positioned on the base 10 as already described. The other cable is prepared in a similar manner, but the insulation is removed from both sides of the cable. This cable is placed over the first, and the subsequent action of attaching the cover of the connector causes the conductors of the two cables to be forced into contact with one another. Because of the low-rate spring effect of the contact member 35, the combined thickness of the two cables does not usually lead to an unacceptably high contact pressure, but if any adjustment is required this may be made by replacing strip 22 by a strip of different thickness.

If a simple tee-junction between two cables is required then the terminal posts 18 of the connection members will not be used. It is of course, possible to omit contact members and/or connection members in positions where connection is not required, and the insulation 41 need not be removed in such positions.

Alternative materials may be used for the body and cover members, and other arrangements may be made for fastening the two together. The hard insulating strip Finally, the cover is pressed into place on the base so I that the books 34 engage in the notches 15 in the spig ots and the tongues 32 become fully engaged under the tops 21 of the posts 20. The action of pressing the cover into place causes the heel 38 of each contact member 35 to press down upon the conductor directly underneath it. Thus contact is made between the conductor 40 and the heel 38 of contact member 35, and thence from the toe 37 of contact member 35 to the top 21 of post 20. The mechanical force is taken between the post 20 of the connection member and insulating strip 22. l

The shape of the contact member results in a high contact pressure, due to the magnification through the lever of the force necessary to fasten the two parts 10 and 30 of the connector to one another. The resilient portion of the contact member 35 also acts as a lowrate spring, thus rendering the contact pressure reasonable independent of variations in dimensions of the casing, thickness of the cable, or creepage in use. The engagement of the two parts also causes the heel 38 of the contact member 35 to rub on the conductor 40, aiding the disruption of tarnish films on the contacting surfaces.

To dismantle the connector, a special tool is inserted into the apertures 39 in the cover 30 to release the books 34. The two parts of the connector may then be separated.

The connector described above is thus able to exert sufficient contact pressure to rupture any tarnish film on the conductors, whilst the force is taken by a pair of metal members 17 and 35 and does not cause any distortion of the connector as a whole. Hence there is no restriction on the overall width of the connector or the number of pairs of conducting members employed.

22 may be omitted.

Instead of cutting apertures 43 in the cable, flaps may be formed which stand up between the terminal posts 20 and the adjacent conductors, thus increasing the tracking distance. i

What we claim is:

1. An electric connector for connection with the con ductors of a flat multiple-conductor cable comprising a first body member of electrically insulating material having means for attaching the cable thereto, a second body member of electrically insulating material securable to the first body member so as to sandwich part of the cable between the two body members, at least one conductive connection member carried by one of the body members, and at least one conductive contact member in the form of a lever having two arms, one arm including a resilient elongated portion and being attached at its end to the other body member, the other arm being engageable at its end with a connection member, the contact member being so shaped that when the two body members are secured to one'another with the cable attached to the first body member a portion of the contact member intermediate the two arms thereof bears upon a conductor of the cable from which the insulation has been removed, thereby connecting said conductor to said connection member.

2. A connector as claimed in claim 1 in which the means for attaching the cable to the first body member includes at least one projecting spigot on the first body member adapted to pass through an aperture formed in the cable between a pair of conductors.-

3. A connector as claimed in claim 2 in which each conductive connection member is carried by the first body member and has a projecting post adapted to pass through a further aperture formed in the cable between a pair'of conductors.

4. A connector as claimed in claim 3 in which the second body member carries at least one tongue for engagement with the post of a conductive connection member and at least one hook for engagement with aspigot of the first 'body member.

5. A connector as claimed in claim 3 in which each conductive contact member is carried at one end by the minal posts formed integral therewith. 

1. An electric connector for connection with the conductors of a flat multiple-conductor cable comprising a first body member of electrically insulating material having means for attaching the cable thereto, a second body member of electrically insulating material securable to the first body member so as to sandwich part of the cable between the two body members, at least one conductive connection member carried by one of the body members, and at least one conductive contact member in the form of a lever having two arms, one arm including a resilient elongated portion and being attached at its end to the other body member, the other arm being engageable at its end with a connection member, the contact member being so shaped that when the two body members are secured to one another with the cable attached to the first body member a portion of the contact member intermediate the two arms thereof bears upon a conductor of the cable from which the insulation has been removed, thereby connecting said conductor to said connection member.
 2. A connector as claimed in claim 1 in which the means for attaching the cable to the first body member includes at least one projecting spigot on the first body member adapted to pass through an aperture formed in the cable between a pair of conductors.
 3. A connector as claimed in claim 2 in which each conductive connection member is carried by the first body member and has a projecting post adapted to pass through a further aperture formed in the cable between a pair of conductors.
 4. A connector as claimed in claim 3 in which the second body member carries at least one tongue for engagement with the post of a conductive connection member and at least one hook for engagement with a spigot of the first body member.
 5. A connector as claimed in claim 3 in which each conductive contact member is carried at one end by the second body member, the other end of said contact member being engageable with the post of a conductive connection member.
 6. A connector as claimed in claim 1 in which at least some of the conductive connection members have terminal posts formed integral therewith. 